Tianyi Cui
50f0291b93
# Conflicts: # docs/architecture.md # examples/acp-agent/tests/snapshots/bash-spill/session.jsonl # examples/acp-agent/tests/snapshots/escalation-approved/session.jsonl # examples/acp-agent/tests/snapshots/escalation-rejected/session.jsonl # examples/acp-agent/tests/snapshots/hook-cc-pretool-ask/session.jsonl # packages/core/agent-loop/src/loop.ts
2.9 KiB
2.9 KiB
Agent Turn And Step Lifecycle
This sequence is the visual companion to architecture.md. It keeps durable replay facts on session/event and live control/status on agent/*.
sequenceDiagram
participant User
participant Agent
participant Driver
participant Hooks as hook listeners
participant Prompt as ctx.systemPrompt
participant LLM as ctx.llm
participant Tools as ctx.tools
participant Session
participant Persistence
participant SDK as UI or SDK listener
User->>Agent: send(content)
Agent-->>SDK: <code>agent/queued</code>
Agent->>Driver: queued work wakes driver
Driver-->>SDK: <code>agent/status</code> running
Driver->>Session: <code>turn/start</code>
Driver->>Hooks: <code>agent/prompt-submit</code> waterfall
Hooks-->>Driver: allow, block, or add context
Driver->>Session: <code>user/message</code> or rejected <code>turn/end</code>
Driver->>Prompt: <code>system-prompt/assemble</code> waterfall
Driver-->>Driver: <code>agent/pre-step</code> serial checkpoint
Driver->>Session: <code>step/start</code>
Driver->>LLM: <code>agent/request</code> waterfall, then <code>llm/stream</code> waterfall
LLM-->>Driver: StreamChunk*
Driver->>Session: <code>assistant/chunk</code>*
Session-->>SDK: <code>session/event</code> <code>assistant/chunk</code>*
Driver->>Hooks: <code>agent/step-result</code> waterfall
Driver->>Session: <code>assistant/message</code>
Driver->>Tools: classify pending call by executionMode
loop barriers and bounded rolling pool, reclassify before start
opt call starts
Driver->>Session: <code>tool/call</code>
Driver->>Tools: ordered pre, concurrent execute
Tools-->>Session: tool-owned events when applicable
end
opt next model-order result ready
Driver->>Tools: ordered post
Driver->>Session: <code>tool/result</code>
end
end
Driver->>Session: <code>step/end</code>
Driver->>Hooks: <code>agent/turn-continuation</code> waterfall
Driver->>Hooks: <code>agent/turn-stop</code> serial terminal checkpoint
Driver->>Session: <code>turn/end</code>
Driver->>Persistence: <code>session/flush</code> parallel checkpoint
Driver-->>SDK: <code>agent/status</code> idle
The assistant/message edge records every successful provider call, including content-less and max-tokens finishes. Empty content stays out of derived history while the durable anchor retains usage and exact chunk provenance, including an explicit empty source set.
SDK users that need replayable transcript data should consume session/event; agent/* is the live coordination surface for queue/status, prompt interception, request shaping, steering, continuation, and errors.
Maintenance mode: curated Mermaid sequence; exact event signatures live in the generated Cordis catalog.